This paper presents a method for GPS/INS operation in shadowed environments such as urban canyons and rural foliage cover. Shadowing causes a combination of multipath and signal attenuation which results in increased uncertainty in the GPS observables and sometimes complete loss of satellite tracking. Environment layout and the line-of-sight vector to the affected satellite determines the degree o...
View full abstract»

In this paper, the authors investigate how the Carrier to Noise power density ratio (C/N0), platform dynamics, and differing Inertial Measurement Unit (IMU) quality affect the performance of Deeply Integrated (DI) algorithms. Two different DI algorithms are described in detail and analyzed using a high fidelity GPS simulator. The first algorithm is a Vector Delay/Frequency Lock Loop (VD...
View full abstract»

NovAtel Inc. and KVH Industries have jointly developed a commercial grade, single enclosure GPS/INS system. The integrated KVH CG-5100 IMU features fiber-optic gyros and MEMs accelerometers, and provides inertial data at 100 Hz. NovAtelpsilas OEMV3 receiver is the GPS engine. Weighing 5.2 lbs, the combined system will feature the tightly coupled architecture that is a key characteristic of NovAtel...
View full abstract»

The quality of dead reckoning positioning algorithms which are integrating GNSS and INS measurements is a crucial factor for advanced vehicular safety systems. Apart from sensor performances, the most important factor determining this quality is the filter algorithm. Thus, this paper aims to compare and evaluate different nonlinear filtering approaches, focusing on their performance in GNSS/INS in...
View full abstract»

This document describes the rationale and methodology behind the application of a Kalman-type filter to a system that has two properties which lead to inaccuracy or instability in traditional filters: highly non-linear system models along with a state that is constrained to a non-linear Riemannian manifold. The non-linear models are handled by the use of the unscented transformation, while the con...
View full abstract»

The extended Kalman filter (EKF) is widely used for the integration of measurements form the Global Positioning System (GPS) and inertial navigation system technologies. The EKF is applied to nonlinear systems via a linearization of the system, and is reliable for weakly linear systems. For strong linear systems however, the EKF sometimes suffers from divergence. To overcome this shortcoming the s...
View full abstract»

The first studies for the mobile mapping and creation of a vehicle for this kind of research were carried out by Canadian Researchers in the 1980psilas. Since then these vehicles have been widely employed in several applications (road cadastre maps, terrestrial photogrammetry, road sign recognition etc.) for both commercial and research purposes throughout the world. Many GNSS/INS vehicles which c...
View full abstract»

This paper presents a new way to apply Gaussian mixture filter (GMF) to hybrid positioning. The idea of this new GMF (efficient Gaussian mixture filter, EGMF) is to split the state space into pieces using parallel planes and approximate posterior in every piece as Gaussian. EGMF outperforms the traditional single-component positioning filters, for example the extended Kalman filter and the unscent...
View full abstract»

Wearable inertial sensors present designers with additional challenges not seen in conventional systems where power at fixed voltage is abundant. This work discusses the critical concerns in designing a wearable inertial sensor including component selection, power distribution and the use of sleep/shutdown modes.
View full abstract»

Eyeball (EB) is a helmet-mounted cueing system used to display cueing symbology for target designation and location on a helmet-mounted display. In order to provide information and interact with the environment, the EB consists of two basic subsystems: a helmet-mounted inertial sensor unit that measures the accelerations and angular rates at which the head of the pilot is exposed and a helmet moun...
View full abstract»

Northrop Grumman, LITEF is developing MEMS (micro-electro-mechanical systems) based Inertial Measurement Units (IMU) for future attitude and heading reference systems (AHRS) with a target accuracy of 5 deg/h for the gyroscopes and 2.5 mg for the accelerometers. Within the technology development phase, prototype single axis gyroscopes have been realized and extensively tested for effects including ...
View full abstract»

Smart munitions and missiles are increasingly incorporating inertial measurement units for guidance of short range weapon systems. In addition to usual high performance of the required sensors, namely, accelerometers and gyros, this application requires high shock survivability and post shock stability of the sensors. Colibrys has successfully developed a gun hard version of its accelerometer prod...
View full abstract»

A set of all-digital metallic cylindrical CVGs of different diameters are presented in this paper. Innalabs CVG43 with resonator diameter of 43 mm, having natural frequency in the range 3 kHz and made of low damping and temperature stable material, is placed under vacuum cap with residual pressure of about 5 times 10-4 arm. The resonator Q factors reach values of 20000 - 30000 depending...
View full abstract»

When pseudolites are used, as in the wide area augmentation system (WAAS), or, when a Locata type array is used for accurately positioning of ground vehicles, a high vertical GDOP is invariably encountered. The latter translates into poor altitude estimates and potentially also poor position estimates, even in the case of a good planar geometry and where the user is near the center of the pseudoli...
View full abstract»

This paper describes the development of a real-time navigation system, embodying high precision navigation equations, which was designed, built, and used by QinetiQ specifically for comprehensive hardware-in-the-loop testing of the STANAG 4572 inertial measurement unit interface standard. The results provided give confidence that the STANAG 4572 interface is fundamentally more than adequate for im...
View full abstract»

Nowadays more and more services rely on the positioning and time synchronization provided by the U.S. Global Positioning System (GPS) which is worldwide available. The requirements on accuracy are increasing with the number of applications using a Global Navigation Satellite System (GNSS). As more systems in transport, communication and other areas are based on GNSS a degradation of performance mi...
View full abstract»

Significant progress has been made in recent years in wavefront technology using Global Positioning System (GPS) simulators. We demonstrate here a novel approach to surpassing some of the limiting obstacles that plague the simulation world in achieving notable carrier-phase parameters. The controlled reception pattern antenna (CRPA) realistically collects and sends the RF downlink data to the ante...
View full abstract»

Location based services (LBS) are currently enjoying a strong success as a result of well-proven GNSS positioning technology (GPS, assisted GPS). However, the future generation of LBS will have to address the challenge of accurate and reliable indoor localization. In fact, this need has already been clearly expressed by various communities of professional end users (firemen, security forces, etc.)...
View full abstract»

In this paper we present a novel radio location system for indoor tracking and navigation. The system has been designed for applications such as emergency first responders where high accuracy is required, all nodes have only wireless connections, and the system must be able to be rapidly deployed. The application requirements are best satisfied using time-of-arrival based radio location, however t...
View full abstract»

The simultaneous localization and learning (SLL) is an indoor localization technique based on existent radio communication networks. It originally takes received signal strength (RSS) as measured feature, used as input on an adaptive and iterative process based on Kohonen self organizing maps (SOMs) in order to learn and improve a feature map. The present paper points the main characteristics from...
View full abstract»

Estimating the location of people and tracking them in an indoor environment poses a fundamental challenge in ubiquitous computing. The accuracy of explicit positioning sensors such as GPS is often limited for indoor environments. In this study, we evaluate the feasibility of building an indoor location tracking system that is cost effective for large scale deployments, can operate over existing W...
View full abstract»